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| author | James Morris <james.l.morris@oracle.com> | 2014-11-19 21:32:12 +1100 |
|---|---|---|
| committer | James Morris <james.l.morris@oracle.com> | 2014-11-19 21:32:12 +1100 |
| commit | b10778a00d40b3d9fdaaf5891e802794781ff71c (patch) | |
| tree | 6ba4cbac86eecedc3f30650e7f764ecf00c83898 /arch/arm/include/asm/mcs_spinlock.h | |
| parent | 594081ee7145cc30a3977cb4e218f81213b63dc5 (diff) | |
| parent | bfe01a5ba2490f299e1d2d5508cbbbadd897bbe9 (diff) | |
Merge commit 'v3.17' into next
Diffstat (limited to 'arch/arm/include/asm/mcs_spinlock.h')
| -rw-r--r-- | arch/arm/include/asm/mcs_spinlock.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm/include/asm/mcs_spinlock.h b/arch/arm/include/asm/mcs_spinlock.h new file mode 100644 index 00000000000..f652ad65840 --- /dev/null +++ b/arch/arm/include/asm/mcs_spinlock.h @@ -0,0 +1,23 @@ +#ifndef __ASM_MCS_LOCK_H +#define __ASM_MCS_LOCK_H + +#ifdef CONFIG_SMP +#include <asm/spinlock.h> + +/* MCS spin-locking. */ +#define arch_mcs_spin_lock_contended(lock) \ +do { \ + /* Ensure prior stores are observed before we enter wfe. */ \ + smp_mb(); \ + while (!(smp_load_acquire(lock))) \ + wfe(); \ +} while (0) \ + +#define arch_mcs_spin_unlock_contended(lock) \ +do { \ + smp_store_release(lock, 1); \ + dsb_sev(); \ +} while (0) + +#endif /* CONFIG_SMP */ +#endif /* __ASM_MCS_LOCK_H */ |